I have written a Perl script to put back some SNMP values, which works fine. I have now written a script on the remote server and used the extend function in SNMP to put the value from the script into SNMP.
If I run:
snmpget -v2c -c public 10.0.0.10 'NET-SNMP-EXTEND-MIB::nsExtendOutput1Line."cc_power"'
I get the result:
NET-SNMP-EXTEND-MIB::nsExtendOutput1Line."cc_power" = STRING: 544
But when I try to use my script to get the information back it doesn't get it. Here is the script:
#!/usr/bin/perl
use strict;
use SNMP;
use RRDs;
my $rrd_db = "/storage/db/rrd/cc_power.rrd";
my $sess;
my $val;
my $error;
$sess = new SNMP::Session(DestHost => "10.0.0.10", Community => "public", Version => 2);
my $power = $sess->get('NET-SNMP-EXTEND-MIB::nsExtendOutput1Line.\"cc_power\"');
$error=RRDs::error;
die "ERROR while updating RRD: $error\n" if $error;
my $date=time;
print "Data Script has been run - Output: ${date}:${power}\n";
but nothing is returned, and I have no idea why... no errors or anything, have I missed something stupid?
Hope someone can help as this is driving me nuts :)
I assume that you used netsnmp snmpget. Well, it hides too many details from you, as it loads MIB documents in background and nicely translate OIDs and SNMP values to all kinds of user friendly formats.
So next time pay attention to what decoration it performs and simulate that in your own code to achieve the same effects.
Related
I have to connect my Perl script to a newly constructed Sybase server version - 16.0.03.08.1019
Error - login Failed (due to encrypt password issue)
Previously the script was written in Perl:
$conn = Sybase::DBlib->new($user,$pass,$server,"$dbase Handle");
$conn->sql("use $dbase");
I searched online every where it is written put EncryptPassword=1.
I tried two ways shown below, but couldn't succeed.
$conn = Sybase::DBlib->new($user,$pass,$server,"$dbase Handle","EncryptPassword=1");
$conn = Sybase::DBlib->new("EncryptPassword=1",$user,$pass,$server,"$dbase Handle");
My question is, where to use EncryptPassword=1 in Perl script. Am I using it in correct place.
Wow! DBlib - that takes me back. When I last worked with DBlib (in about 1995), one of the tasks on my list was to replace all use of DBlib with CTlib - which was Sybase's new technology that was intended to replace DBlib. Soon after that, the system was rewritten again to use DBI and DBD::Sybase - which has been the recommended way to talk to Sybase databases from Perl programs for over twenty years. You'll note that the most recent release of sybperl (which is the CPAN distribution containing Sybase::DBlib and Sybase::CTlib) was over ten years ago. I'm pretty sure that Sybase themselves haven't supported DBlib since about the start of this millennium.
So, bearing in mind that you're using ancient technology that is largely dead and shouldn't be used, is there anything that can be done to help you without rewriting the whole system?
Perhaps.
Looking at the documentation for Sybase::DBlib, I see this example of how to write calls to new():
$dbh = new Sybase::DBlib [$user [, $pwd [, $server [, $appname [, {additional attributes}]]]]]
Ignore the fact that it's using the new Class syntax that any rational programmer would avoid - the Class->new() version is this:
$dbh = Sybase::DBlib->new([$user [, $pwd [, $server [, $appname [, {additional attributes}]]]]])
Note the "additional attributes" field at the end. I bet that's where your stuff needs to go. Note also, that it's { additional attributes } - so it looks like it expects a hash reference.
So it seems likely that the syntax you want is this:
$conn = Sybase::DBlib->new($user, $pass, $server, "$dbase Handle", {
EncryptPassword => 1,
});
Note that there are huge caveats in this. Not least, given that Sybase::DBlib has been unsupported for ten years, I wouldn't be at all surprised if it didn't support encrypted passwords at all.
But it might work. It's probably your best hope.
And please do whatever you can to update your codebase to use tools and libraries that haven't been unsupported for such a long time.
I am applying the cicindela2 recommendation engine
It uses Apache mod_perl and the Perl DBI module.
Here is the rough flow of how it works
Data input by Record Handler
Data is passed through the filter chain for batch processing
Temporary tables are output from batch processing
Recommendation result is requested by accessing the Recommend Handler which trigger the action of Recommender
I configured an aggregation and ran the project batch script. I know that the batch processing succeeded because I saw the output of processing from DB. But when I tried to access the recommendation result with URL that triggers the Recommend Handler, I saw a blank white page and the log said
FATAL: Insecure dependency in parameter 1 of DBIx::ContextualFetch::db=HASH(0x7f2a76169e78)->prepare_cached method call while running with -T switch at /usr/local/share/perl5/Ima/DBI.pm line 398.
This is where the error was thrown from the
Ima::DBI
base module
/usr/local/share/perl5/Ima/DBI.pm.
sub _mk_sql_closure {
my ($class, $sql_name, $statement, $db_meth, $cache) = #_;
return sub {
my $class = shift;
my $dbh = $class->$db_meth();
# Everything must pass through sprintf, even if #_ is empty.
# This is to do proper '%%' translation.
my $sql = $class->transform_sql($statement => #_);
return $cache # Line 398
? $dbh->prepare_cached($sql)
: $dbh->prepare($sql);
};
}
It seems that the SQL query prepared by the program is insecure, right?
What is reason for this error?
Is it related to the function of cache management of DBI?
Would it be solved if I clear the cache regularly?
Also, I tried to log the SQL statement generated, but the output failed even when I placed something like $LOGGER->warn("123") in the handle subroutine of the Recommend Handler.
How come the log failed and how to log it correctly?
Insecure dependency... while running with -T switch is Perl's way of telling you that you're running with taint mode active and attempting to do something with tainted data which could be potentially unsafe. In this particular case, $sql is tainted, because some or all of its content came from sources external to the program - probably user input, although it could also have been read from a file.
To fix this, you need to think about where $sql came from, so that you can work out the appropriate way to clean it up.
In the most likely scenario, you've asked a user to supply search terms and then inserted those terms directly into your SQL string. This is a bad idea in general, as it opens you up to the possibility of SQL injection attacks. (Obligatory Bobby Tables link.) Revise your SQL handling to make use of SQL placeholders instead of inserting user input into the WHERE clause and this vulnerability should go away.
If tainted data is making its way into $sql in some other way, you need to clean up the tainted data by using a regular expression to validate it and capture the validated data, then assign the captured data to your variable. e.g.,
my $tainted = <STDIN>;
$tainted =~ /([A-Z]*)/; # Only allow uppercase characters
my $clean = $1; # No longer tainted because it came from $1
If you need to take this route, DO NOT use .* as your regex to untaint the data without serious, serious consideration, because, if you just blindly accept any and all data, you will be discarding any and all benefit provided by taint mode.
i want to write a little script to grab and play around with the results of the autocomplete of an input field.
So I find a principal solution with Selenium::Firefox, that base on module Selenium::Remote::Driver, but the description of the methods is without any examples.
I have this basic example, that is able to open google and insert a search string.
Then you can see that a result list is suggested and i want to get this list.
But i have no idea how this can be obtained?
Here is my code so far:
#!/usr/bin/perl
use strict;
use warnings;
use Selenium::Firefox;
my $mech = Selenium::Firefox->new(
startup_timeout => 20,
firefox_binary => '/srv/bin/firefox.62.0/firefox',
binary => '/usr/local/bin/geckodriver',
marionette_enabled => 1
);
my $search = "perl";
my $url = "https://www.google.com/";
$mech->get($url);
$mech->find_element_by_name("q");
sleep(3);
my $result = $mech->get_active_element();
$result->send_keys($search);
sleep (10);
$mech->shutdown_binary;
exit 0;
I could find no examples to use this Perl module - and there are more questions for it.
As for instance: find_element
How can i turn on the warnings instead of killing the script?
Or how can i step through the objects of the wep page?
Is it possible to connect to an already opened browser?
The description of the module is not understandable for people who are not experts and the authors did not answer to questions so far.
But my hope is that experts here can give me a hint?
I am desperately trying to find an easy way to regulary check if a PGSQL server is still alive from within a perl script. I intended to use pg_ping for this, but in my tests pg_ping always returns 1, independently of the DB server status.
Here's the code I tried it with:
#!/usr/bin/perl
use strict;
use warnings;
use DBD::Pg;
my $dbh=DBI->connect("DBI:Pg:dbname=healthcheck;host=vm0484","healthcheck","areyoustillthere");
for (my $i=1;$i<100;$i++) {
print "$i. pg_ping: ".$dbh->pg_ping."\n";
sleep(1);
}
I then used kill -9 in another window to manually terminate the PGSQL-server, but the result was still 1. Did I do something wrong?
If not, how do I best check, if the DB server is still alive?
Thanks in advance.
You can manually perform query like
select 1 as is_alive
as ping() also claim to do something similar,
The ping method issues an empty query and checks the result status.
I'm in a web scripting class, and honestly and unfortunately, it has come second to my networking and design and analysis classes. Because of this I find I encounter problems that may be mundane but can't find the solution to it easily.
I am writing a CGI form that is supposed to work with a MySQL DB. I can insert and delete into the DB just fine. My problem comes when querying the DB.
My code compiles fine and I don't get errors when trying to "display" the info in the DB through the browser but the data and text doesn't in fact display. The code in question is here:
print br, 'test';
my $dbh = DBI->connect("DBI:mysql:austinc4", "*******", "*******", {RaiseError => 1} );
my $usersstatement = "select * from users";
my $projstatment = "select * from projects";
# Get the handle
my $userinfo = $dbh->query($usersstatement);
my $projinfo = $dbh->query($projstatement);
# Fetch rows
while (#userrow = $userinfo->fetchrow()) {
print $userrow[0], br;
}
print 'end';
This code is in an if statement that is surrounded by the print header, start_html, form, /form, end_html. I was just trying to debug and find out what was happening and printed the statements test and end. It prints out test but doesn't print out end. It also doesn't print out the data in my DB, which happens to come before I print out end.
What I believe I am doing is:
Connecting to my DB
Forming a string the contains the command/request to the DB
Getting a handle for my query I perform on the DB
Fetching a row from my handle
Printing the first field in the row I fetched from my table
But I don't see why my data wouldn't print out as well as the end text. I looked in DB and it does in fact contain data in the DB and the table that I am trying to get data from.
This one has got me stumped, so I appreciate any help. Thanks again. =)
Solution:
I was using a that wasn't supported by the modules I was including. This leads me to another question. How can I detect errors like this? My program does in fact compile correctly and the webpage doesn't "break". Aside from me double checking that all the methods I do use are valid, do I just see something like text not being displayed and assume that an error like this occurred?
Upon reading the comments, the reason your program is broken is because query() does not execute an SQL query. Therefore you are probably calling an undefined subroutine unless this is a wrapper you have defined elsewhere.
Here is my original posting of helpful hints, which still apply:
I hope you have use CGI, use DBI, etc... and use CGI::Carp and use strict;
Look in /var/log/apache2/access.log or error.log for the bugs
Realize that the first thing a CGI script prints MUST be a valid header or the web server and browser become unhappy and often nothing else displays.
Because of #3 print the header first BEFORE you do anything, especially before you connect to the database where the script may die or print something else because otherwise the errors or other messages will be emitted before the header.
If you still don't see an error go back to #2.
CGIs that use CGI.pm can be run from a command line in a terminal session without going through the webserver. This is also a good way to debug.